Warrants for Traffic Control Devices

A warrant for any traffic control device (sign, signal or pavement marking) is the minimum criteria that must be met before such a device can be installed. Meeting a warrant does not mean a traffic control device must be installed. The Michigan Manual of Uniform Traffic Control Devices spells out these warrants to ensure that each device:

Fulfills a need

Commands attention

Conveys a clear, simple meaning

Commands the respect of road users

Gives adequate time for proper response

Traffic Signals

Traffic Signals have 11 warrants, at least one of which must be met before a signal can be installed. These warrants state the number of vehicles, pedestrians, crashes or combination of these that must exist before a signal can be installed.

Stop Signs

Stop Signs have their own set of four Warrants:

Intersections of a less important road with a main road where the normal right-of-way rule is unduly hazardous

Street entering a through highway or street

Unsignalized intersection in a signalized area

Other intersections where a combination of high speed, restricted view and serious crash record indicates a need for control by the stop sign

Prior to the application of these stop sign warrants, consideration should be given to less restrictive measures, such as a yield sign. Any devices that are not in the manual are not traffic controls and cannot be used. These include "slow children" and "slow" signs. In addition to meeting the warrants, regulatory signs (stop, speed limits, parking, etc.) must also have an official Traffic Control Order signed by the traffic engineer and filed with the local clerk. The decision to install a traffic control device should be made on the basis of an engineering study, the warrants and engineering judgment by a qualified traffic engineer. Effective and safe traffic control depends on the appropriate application of traffic control devices and reasonable law enforcement. These warrants are based on that concept. Provided by: